The present invention relates to apparatus which, in photographic film manufacturing processes, applies characters, symbols or the like such as manufacturer's film type, frame number, expiration date, production lot number, and the like to the marginal portions of film strip.
In such apparatus which are generally called side printing apparatus, there is provided a light image forming device having a number of light emitting elements disposed in matrix arrangement which can form a light image of dot pattern to be exposed on the photographic film and thereby provided as a latent image. Such apparatus are more fully disclosed in Japanese Utility Model unexamined publication No. 76,929/1978 and Japanese Patent unexamined publication No. 163,266/1982.
The apparatus described above is attended with an unavoidable shortcoming characterized by the provision of a number of driving circuits and connecting wires for the respective light emitting elements. As a result, it follows that the apparatus is of great bulk and high manufacturing cost. Furthermore, it is difficult to make a number of light emitting elements uniform in brightness.